You say Serve Allah by being obedient to His commands & Follow His guidence.Ok it is fine but does it not mean to pray or worship? Praying or worshiping are having connection with the Creator & praising Him but our actual duty is to act as Allah has commanded in our daily life.I also wanted to stress here that idols do not give any commands to serve or follow, therefore it is worshipping or praying that is being mentioned in this surah.Thanks for sharing